Welcome to HVAC-Talk.com, a non-DIY site and the ultimate Source for HVAC Information & Knowledge Sharing for the industry professional! Here you can join over 150,000 HVAC Professionals & enthusiasts from around the world discussing all things related to HVAC/R. You are currently viewing as a NON-REGISTERED guest which gives you limited access to view discussions

To gain full access to our forums you must register; for a free account. As a registered Guest you will be able to:

Participate in over 40 different forums and search/browse from nearly 3 million posts.

Can Someone confirm my diagnosis?

Hello Everyone, I was hoping someone could help out a lowly homeowner , and verify my diagnosis to my furnace issue.

I have a Rheem RGDG-07EAUER furnace.

Two things are happening. The first issue is that the furnace shuts down before the desired temperature is reached. This happens intermittently. The furnace runs fine for a day, then cuts out the next during the morning Call for Heat. I've tried two thermostats, but I have yet to verify that the board is receiving the 24v at the time it cuts out.

The more persistent problem is that during the initial ignition sequence, the draft fan starts up fine, the ignitor glows, and then the gas valve opens and closes in a fraction of a second. I have verified that the 24v is sent to the valve for only this split second. I do not believe it is a flame sensor issue, as the time it takes to open and close is shorter than the time it takes to normally ignite, so if it was a flame sensor issue, i'd think it would be not working all time, instead of intermittently. I have verified that the valve is recieving the constant 24V when it is working correctly.

From what I can tell this problem just seems to be a faulty control board. Are miscellaneous issues like this a typical symptom?

I've replaced a board before in another furnace, but the place I purchase from allows no returns, so I'm a little hesitant to drop the $ before being sure that will fix the issue.